Vehicle manufacturers have concerned themselves with child security features on door latches, and especially rear door latches. Presently there are several types of child security locks for disabling the rear inside door latch handle of a vehicle.
One type of security lock involves a hand-operated lever that pivots into and out of engagement with the door latch components. The purpose of the lever is to engage one or more of these components to block or arrest motion transfer along the motion transfer path between the rear inside door latch handle and the latching assembly that unlatches the rear door. In order to operate the lever, a person must open the rear door to access the lever, which is located adjacent the door latch.
Another type of hand-activated system is a free-wheeling system. In such a system, some of the motion-transferring components in the latch's motion transfer path can switch into a free-wheeling or lost motion mode wherein they do not transfer motion from the inside latch handle to the latching assembly.
These manually operated systems are effective; but they lack convenience. For example, the driver may want to activate the security lock while seated in the vehicle--perhaps even while driving. This is not possible without a power system for activating the lock, with a switch located near the driver seat.
There are power security lock systems of the type shown in U.S. Pat. Nos. 5,511,838 to Baughman et al; and 5,263,751 to Priest et al. These systems each involve an electromechanical assembly disposed in the motion transfer path between the inside latch handle and the latching assembly. But in both cases the electro-mechanical assembly is positioned in the middle of the door--mid-way between the latch handle and the latching assembly. Both systems involve establishing a free-wheeling junction along the motion transfer path between the inside latch handle and the latching assembly. Thus, when the lock is activated, the motion transfer path is broken, and the inside latch handle will simply free-wheel. These two power systems are effective, but they leave room for improvement in the area of simplicity and packaging. Both are complex assemblies involving several parts; and both involve installation in the middle of the door and remote from the latching assembly. This translates into higher labor and material costs, and possibly higher vehicle weight.